It is known that one of the challenges in the design of replaceable filter systems is to create a reliable attachment and seal on a receiving means to which the filter system is attached. The mechanical interfaces should have as simple a design as possible, yet be robust and reliable. It should be possible to repeatedly replace the filter system as simply, quickly and unproblematically as possible. Moreover, it is intended to cover a plurality of installation situations having similar solutions in order to be able to provide cost-effective filter systems.
Fuel filters normally use a disposable filter element that is replaced after predetermined filter usage time intervals. The disposable element is conventionally attached to the base structural component of the filter via a retaining or latching mechanism that is releasable so as to permit the removal of the element for replacement purposes. There is a plurality of conventional base part retention systems for fuel filter elements. Many such retaining systems are very inconvenient to use or even fail after a time because of the harsh environment surrounding the fuel filter insert.
U.S. Pat. No. 5,302,284 A describes a filter structure that includes a base part, a filter element attachable to the base part and a retaining collar for attachment of the filter element to the base part. The collar holds a wave spring which is retained between spaced-apart shoulders of the collar. The base part forms a receiving means device for holding the head of the filter element. A ramp and a catch, which is adjacent to the end of the ramp, are arranged in front of the base part. The retaining collar further includes a cam which has a detent. The cam is engageable with the ramp, so that if the collar is turned at an angle, the cam moves on the ramp and the detent engages in the catch under the prestress of the spring in order to lock the filter element on the base part.